26 INHERITANCE OF SOME CHARACTERS IN WHEAT. 



The red grained parent, Punjab Type 9, was found to be identical 

 with the eleventh standard and the ¥ 1 in all cases was intermediate 

 between standards 5 and 6. The bulk of the plants in the F 2 ap- 

 pear in the centre of the curve. The curves obtained from the 

 individual crosses agree very fairly well with each other and with the 

 compound curve, especially if the difficulty of matching these slightly 

 varying shades of red be taken into account. All the observations 

 on this question both in the F 2 and F 3 generations were carried out 

 by the same observer in order to minimise the personal equation. 

 A large number of F 2 plants, representative of all the various 

 tones of red in the series, were then sown singly seed by seed and the 

 resulting harvest examined in the same manner as the F 2 . By this 

 examination it was possible to identify the two shades of red repre- 

 senting the two factors R a and R 2 and to isolate wheats which, in all 

 probability, contain each factor singly. It was found that the F 3 

 cultures derived from F 2 plants with grain belonging to the classes 

 represented by standards 1 and 2 in all cases gave a ratio of 3 red 

 grained to 1 white grained plant, the darkest red tone obtained being 

 never higher than 5. The F., plants represented by standards 3 

 and 4 also gave the 3:1, but in each case some plants bred true to 

 red and gave uniform progeny with pale red grains. A few plants 

 giving the same pale red uniform progeny were also derived from 

 standard 5, but generally speaking after standard 4 there is a distinct 

 change in the nature of the F 3 cultures. Ratios of 15 red grained 

 to 1 white, were obtained from standard 5 as well as some with 3 red 

 to 1 white, but in this case the red tones ranged as high as standard 9. 

 It is clear that in the region of the curve, in which standards 3 and 4 

 occurred, one of the red factors was to be found and this was repre- 

 sented by the pale constant reds obtained. The pale red F 2 plants 

 represented by standards 1 and 2 which gave the 3 : 1 ratio must 

 have been heterozygotes of the pale red and white gametes. In a 

 similar manner many uniform red plants occurred at 9 and a few 

 at standard 8. These were a full red and represented the other red 

 factor. The plants in standard 5 which gave the 3 : 1 ratio with 

 red tones up to standard 9 must'have been heterozygotes of the dark 

 red and white factors. The reds which were not uniform were met 



